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 CSB
Investigation into Massive Explosion Concludes Lack of
Company Safeguards Allowed Solvent Vapor to Accumulate
When Ink-Mixing Tank Was Left Heating Overnight
USA -- Changes Urged to National Fire Codes, State Licensing and Inspection
Procedures to Improve Safety of Facilities Handling
Hazardous Materials
A
massive explosion and fire at the CAI/Arnel ink and
paint products manufacturing facility in November 2006
occurred because CAI lacked safeguards such as alarms
and automatic shutoffs that would have prevented a
10,000-pound mixture of flammable solvents from
overheating in the unattended building, investigators
from the U.S. Chemical Safety Board (CSB) said in a
final draft report made public today.
Steam
heat to the mixing tank was most likely inadvertently
left on by an operator before he left for the day. As
the temperature increased, vapor escaped from the mixing
tank, built up in the unventilated building, ignited,
and exploded.
The
105-page report is set to be considered by the
four-member Board at a public meeting in Danvers this
evening, beginning at 6:30 p.m. at the North Shore
Ballroom of the Sheraton Ferncroft Hotel,
50 Ferncroft Road. The meeting is free and open to the
public. Members of the public are encouraged to attend
and comment on the draft report prior to the Board's
consideration. The meeting is expected to conclude at
approximately 9:30 p.m.
Following a detailed presentation by the CSB
investigators, including a new ten-minute video of the
explosion and its impact on the community, local and
state officials and a Danversport resident are scheduled
to present testimony to the Board describing changes to
oversight of manufacturing facilities following the
accident.
CSB
investigators said that ink manufacturer CAI did not
follow regulations or appropriate good practices for the
handling of flammable solvents, and the CSB report
proposes changes to national fire codes and to state
licensing and inspection procedures to improve the
safety and oversight of facilities handling hazardous
materials.
Investigators said that on the night of the accident,
ink base materials - including a volatile mixture of
heptane and propyl alcohol - continued to heat and then
boil after all the employees left work late in the
afternoon. The heating was controlled by a single,
manual valve that needed to be closed by an operator to
prevent the 3,000-gallon tank from overheating.
The
building ventilation system was turned off at the end of
the workday - a routine procedure - and vapor coming out
of the unsealed tank spread throughout the production
area and then ignited from an undetermined source,
possibly a spark from an electrical device. The
explosion occurred at approximately 2:46 a.m. on
November 22, 2006.
The
blast ripped through the adjacent Danversport
neighborhood, waking sleeping residents as windows were
blown into
bedrooms and shattered, ceilings fell, and belongings
and appliances flew about. The blast wave damaged
scores of homes. At least 16 homes and three businesses
were damaged beyond repair, and approximately ten
residents required hospital treatment for cuts and
bruises. The fire department ordered the evacuation of
more than 300 residents within a half-mile radius of the
facility.
'The
community damage was the worst we have seen in the
ten-year history of the Chemical Safety Board,' said CSB
Board Member William Wright, who accompanied the
investigative team to the accident site. 'As others have
noted, this explosion had a serious potential for
life-threatening injuries and fatalities.'
The
facility, shared by ink manufacturer CAI and paint
manufacturer Arnel, was completely destroyed by the
explosion and ensuing fire and has not been rebuilt.
Arnel ceased operations, while CAI continues to produce
water-based inks at a facility in Georgetown,
Massachusetts.
Mr.
Wright said, 'The immediate cause of the accident was
the overheating of a highly flammable mixture for many
hours. We found an underlying cause was CAI's failure
to conduct a hazard analysis or other systematic review
to ensure flammable liquids were safely handled during
the manufacturing process.'
'The
company did not have automated process controls, alarms,
or other safeguards in place. The standard practice at
the company was to shut off ventilation at night - to
retain heat in the building and to allay residential
complaints about fan noise,' Mr. Wright said. 'When the
mixture continued to overheat - absent automatic
shutoffs and proper ventilation - the vapor accumulated
and
filled much of the building over a period of hours.
Without safeguards, it is likely that a small but
foreseeable human error led to disaster.'
CSB
Lead Investigator John Vorderbrueggen, P.E., said
Massachusetts state fire regulations and local
enforcement should be improved to better protect
communities and employees. He said, 'The existing
Massachusetts fire codes - as well as federal OSHA
standards - have requirements for ventilation of
flammable vapors to prevent dangerous accumulations
inside structures. But Massachusetts has not adopted
the most current national fire codes for flammable
liquids. Our investigation also found that while the
state requires local fire departments to periodically
inspect facilities that handle flammable materials, the
laws do not specify any inspection frequency or criteria
for conducting those inspections.'
The
CAI/Arnel facility was last inspected by the fire
department in 2002, but the inspection focused on a
newly installed fire suppression system and did not
identify fire code or permitting violations. In
addition to the inadequate ventilation that contributed
to the accident, non-causal fire code violations
included improper venting of flammable storage
containers, use of improper hoses for flammable service,
and lack of fire walls.
Under
the General Laws of Massachusetts, the CAI/Arnel
property was required to have land-use licenses for
flammable materials. The only license, first issued to
a predecessor company in 1944 and re-registered annually
thereafter, initially authorized the presence of 250
gallons of 'lacquer.' In 1955, the property owners were
granted an amended license by the Danvers Board of
Selectmen to store and use 6,000 gallons of
'miscellaneous' flammable materials.
By the
time of the accident in 2006, the registration record on
file with the Town of Danvers referenced a 'license' to
store and handle up to 11,500 gallons of 'miscellaneous'
flammable materials. However, the CSB found no record
of such a license in the Danvers town files. Therefore,
the CSB concluded, the current licensed amount was 6,000
gallons, well below the more than 20,000 gallons of
flammable liquid and more than 50,000 pounds of
flammable solid, nitrocellulose, stored on site.
The
CSB found Massachusetts law to be unclear on the
requirements and procedures for towns to approve
requests for
increasing the amounts of flammables to be stored at
industrial sites, including whether or how adjacent
property owners should be notified of intended
increases. The investigation also pointed out that the
state's licensing and registration forms do not require
information on the specific types and quantities of
materials stored.
A CSB
survey of six Massachusetts municipalities - including
Boston, Worcester, Springfield, Danvers, Leominster, and
Georgetown - found significant variability in how state
licensing and registration laws are applied. Although
the six municipalities issued a total of more than 400
flammable materials licenses, only two reported ever
having denied a license application.
In
addition to a license, Massachusetts regulations require
companies to obtain separate permits from the local fire
department for the storage of flammable liquids, gases,
and solids. However, at the time of the explosion in
Danvers, no permits had been obtained by or issued to
CAI or Arnel, except an expired permit for underground
storage tanks. The lack of permits had not been
previously identified by the fire department.
Based
on the quantities of flammable materials used, CAI but
not Arnel was required to comply with OSHA's Process
Safety Management standard, which would have required
the company to conduct a process hazard analysis. Such
a review could have identified the need for more
sophisticated process control equipment, operator
checklists, and continuous building ventilation. The
standard
also requires the use of written operating procedures,
which can reduce the occurrence of human errors.
However, CAI management stated the company was not aware
of the Process Safety Management standard's existence
and had not implemented its requirements. OSHA had not
inspected the facility prior to the accident.
Finally, the report stated that national model fire
codes developed by the National Fire Protection
Association (NFPA) and the International Code Council (ICC)
do not provide sufficient safeguards for flammable
liquids heated inside buildings. The standards - which
are voluntary unless specifically adopted by states and
localities - contain ambiguous language concerning
process vessels and do not explicitly require automatic
shutdown or cooling systems to prevent accidental
overheating and the uncontrolled release of flammable
vapor.
The
CSB investigated a similar accident in 2006 at a
Chicago-area concrete products company, where a vessel
filled with heptane accidentally overheated inside an
unventilated building, causing an explosion that killed
a driver and caused property damage.
The
investigation report makes numerous safety
recommendations, which will be considered by the Board.
The report calls on the NFPA (based in Quincy,
Massachusetts) and the ICC to revise the national fire
codes to prohibit the heating of flammable liquids
inside buildings in unsealed tanks that do not vent
outside and to require automatic safeguards to prevent
overheating.
The
report calls on the Massachusetts legislature to require
companies to certify compliance with state fire codes
and safety regulations, to require public input before
allowing companies to increase the quantities of
licensed flammable materials, and to require the Office
of the State Fire Marshal to audit localities'
compliance with licensing and permitting requirements.
Other
proposed recommendations call on the state's Office of
Public Safety to adopt current national fire codes for
handling flammable liquids (NFPA 30) and manufacturing
of coatings (NFPA 35), to develop standards and a
mandatory frequency for fire department inspections of
manufacturing facilities, and to require license and
registration forms to specifically
list the type and quantity of each hazardous material.
Pending completion of the recommended changes at the
state level, the report calls for the Town of Danvers to
undertake similar initiatives for certification,
licensing, and inspection. Additional, specific safety
recommendations were directed to CAI, in the event the
company resumes solvent-based processing at another
location. The draft report's findings, statements of
cause, and recommendations are all subject to approval
by a vote of the Board and are subject to change.
The
CSB is an independent federal agency charged with
investigating industrial chemical accidents. The
agency's board members are appointed by the president
and confirmed by the Senate. CSB investigations look
into all aspects of chemical accidents, including
physical causes such as equipment failure as well as
inadequacies in regulations, industry standards, and
safety management systems.
The
Board does not issue citations or fines but does make
safety recommendations to plants, industry
organizations, labor groups, and regulatory agencies
such as OSHA and EPA. Visit our
website.
 OSHA
cites Salem power plant owners for fatal explosion
The owners of a Salem power plant are
facing federal citations for alleged safety violations
after a steam explosion last year that killed three
workers.
The Occupational Safety and Health Administration said
today that Dominion Energy New England had failed to
take effective steps at the Salem Harbor Power Station
to protect employees from hazards from ruptured or
leaking boiler tubes and piping.
The federal workplace safety agency also said the area
where the plant's boiler tubes ruptured had not been
entered or inspected in more than nine years.
"The company must initiate and maintain effective
safeguards to identify and eliminate such hazards, both
to protect its employees, and to prevent future leaks,
ruptures, or explosions," Rosemarie Ohar, OSHA's acting
area director in Methuen, said in a statement. "Proper
inspection and maintenance are critical to detecting
potentially dangerous conditions."
The agency said it was issuing a total of 10 citations
for serious violations to Dominion Energy New England
carrying a total of $46,800 in proposed fines. The
company has 15 business days from receipt of the
citations to meet with OSHA or contest the citations and
fines.
A spokesman for Dominion Energy didn't immediately
return a telephone message seeking comment.
Engineer Phillip Robinson, mechanic Mark Mansfield, and
rookie Mathew Indeglia, were killed in the Nov. 6, 2007,
explosion when they were enveloped in a cloud of steam
that approached 600 degrees.
The plant, which is more than 50 years old, recently
started to power up again, following months of work by
Salem Harbor employees, investigators, and cleaning
crews to inspect the plant's machinery and clean up fly
ash and a small amount of asbestos left from the
accident.
The Essex County district attorney's office is also
investigating the accident.
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